The International Cessna 170 Association

Water stains are (for lack of a better word) etched into the aluminum . I’ve used Nushine F7 and it does shine it up but spots remain.

i have had the same issue with my spinner. we have very mineralised water and after washing these spots appear. i have then used 1000 grit paper and slowly advanced to 1500 grit. I was told that tooth paste is good also but haven’t tried that yet. After 1500 grit rubbing all over I then use a metal polish put out by one of the car polish manufactures. I then used a ceramic type polish on the spinner. Stops the water marks .

Thanks

https://nuvitechemical.com/aviation-landing-page/
You can also contact Nuvite for suggestions.

I always used G7 with a rotary 6 inch fleece pad and go back and forth. You can blend it in so it can barely be visible. F series is even more agressive.

I am not an airplane polisher…but if I were….I’d avoid anything with “grit”.

I’ve seen airplanes that have had rivet heads diminished by such use and it weakens the structure.

George, what you probably saw was the results of someone sanding the rivet heads down carelessly, then polishing the metal back. You will not damage a universal rivet head with even the most aggressive Nuvite products unless you really have no idea what you are doing.

Hard water spots are tough. Are you using a single buffing wheel or a Cyclo? I’ve had good results with stubborn water spots using F7 and a buffer with a wool pad. I don’t try to dig into it but instead make multiple passes around the general area until the stains disappear. I had a particularly stubborn stain on top of the wing that took about 4 applications to remove. G6 might be a good option if you need to be more aggressive.
I’ve seen ghost images of water spots while polishing with S but they disappeared nicely after the polish was buffed away.

I’ve also read accounts of Airstream polishers using a vinegar/water mix before polishing. I’ve never tried it, though.

Nuvite doesn’t contain what I call “grit”. Nuvite is good stuff from everything I hear. (Rolite is similar)

Vinegar is acetic-acid and will dissolve calcium, etc. which causes “spots’ when the water dries. Hard water is usually heavy with calcium from limestone. Our water supply at home is a deep well….and the water tastes lovely…makes good bourbon (why Kentucky is famous)… but leaves spots and eventually clogs up the dishwasher and the coffee pot…. so we run a cup of vinegar thru those things about once month.

But acid also etches aluminum so …beware.

(We also have an Airstream and if the Airstream was made since the late ‘90s….it is also clear-coated and should not require deep polishing…. doing so will remove the clearcoat and then you will be STUCK with polishing forever.. If, however, it’s been heavily polished…. new or old Airstreams will need refreshing from time to time…as they are also created using 2024 aluminum.0

Another urban myth is to use a couple of good squirts of WD40 in your water for washing your aircraft. I haven’t tied yet ,but can’t see any harm in the practise.